Ascertaining the correct balance between forage supply and livestock demand is a critical issue for grassland animal husbandry in China. Calculations are typically based on theoretical models that balance energy availability and requirement, and adoption has been hindered by disagreement as to the size and response to various factors of the theoretical coefficients used. In this article we summarize progress in China in livestock feed budgeting research. Adoption of forage-livestock supply and demand calculations based on average net primary productivity and animal feed intake for arid and semi-arid rangeland characterised by uneven precipitation and wide seasonal temperature fluctuation may not deal with the complexity and uncertainty arising from seasonal imbalance between supply and demand within the ecosystem. Despite considerable progress in solving temporal-spatial disequilibrium between grassland productivity and livestock requirement, major challenges remain for “seasonal animal husbandry” and “key pasture”. Parameter estimates commonly used as a basis for forage-livestock balance decision-making require standardisation. In particular, there is no consensus as to the application or method of determining parameters such as livestock substitution rate, livestock numbers, and appropriate stocking rate, among others. In future, research into forage production-livestock demand balance should focus on exploring opportunities to reduce seasonal imbalance between forage supply and livestock demand, and on coordination of the ecological, social and economic functions of grassland.

草畜平衡问题是中国草地畜牧业的核心问题,草畜平衡的理论依据、计算参数存在着争议和分歧。本文主要依据中国载畜量和草畜平衡研究成果,总结了中国草畜平衡研究和实践上的困境。指出以平衡理论为基础的草畜平衡,对主要由降水驱动的干旱、半干旱草地并不具有指导意义。草地生产力时空变异大,根据平均生产力和家畜平均采食量核算的草畜平衡无法做到动态平衡;“季节畜牧业”、“关键场”等理论在解决草畜时空相悖上也充满挑战。家畜单位、存栏数量、合适放牧率等主要估算参数的争议,还不能为草畜平衡实践提供切实可行的决策依据。探索草畜适应性动态管理,协调草地生产的生态、社会和经济功能,应是中国草畜平衡未来的研究重点。

CENTURY model was utilized to simulate the annual aboveground net primary production (ANPP) of Leymus chinensis steppe, a dominant community type in Xilin River basin of Inner Mongolia steppe region. The results showed that the model performed reasonably well in predicting the dynamics of the ANPP. The scenario-based simulations indicated that though the variations of air temperature and precipitation due to global climate change as well as the elevated CO 2 would significantly affect the dynamics of the ANPP, precipitation was the key affecting factor. Several GCM models had predicted that the precipitation in this region would decrease in the future, and consequently, it was likely that the ANPP would also decrease. Nevertheless, the simulation results showed that while the ANPP decreased in most climate change scenarios, it might also increase in the following climate change scenarios: 1) if the atmospheric CO 2 concentration was doubled, air temperature was increased by 2 ℃, and precipitation was kept unchanged or increased by 10%-20%, and 2) if the atmospheric CO 2 concentration was kept unchanged, air temperature was increased by 2 ℃, and precipitation was increased by 20%. Overall, it was evident that climate change would have significant effects on the steppe in Xilin River basin of Inner Mongolia.

利用CENTURY模型对内蒙古锡林河流域羊草草原在未来气候变化以及大气CO 2 浓度增高条件下的年地上净初级生产力(annual aboveground net primary productivity，ANPP)动态进行了模拟研究.结果表明：CENTURY模型可以较好地预测ANPP的变化.进一步的情景模拟发现，虽然全球气候变化所引起的温度和降水改变、以及大气CO 2 浓度升高都会影响ANPP，但降水是关键的影响因子.多个全球气候模型(GCM) 预测该地区未来降水量会减少，故可能导致其ANPP降低，但在以下气候变化情景下研究区ANPP可能会升高：1)CO 2 浓度倍增，温度升高2 ℃，降水保持不变或增加10%～20%；2)CO 2 浓度保持不变，温度升高2 ℃，降水增加20%.气候变化将对内蒙古锡林河流域羊草草原产生显著影响.

摘　要： 草畜平衡制度是我国草原管理和生态保护的基本制度,但在实施中却难以达到＂草畜平衡＂的目的。文章基于内蒙古地区的田野调查和文献资料,从草场生态过程和牧民行为两个方面,分析了草畜平衡制度在实施中问题产生的根源。研究表明：一方面,干旱半干旱草场存在一定的非平衡生态系统特征,承载力管理不一定能实现草场的可持续利用;另一方面,牧民对载畜量的控制是一个多因素影响下的综合决策,并受到市场、畜牧业生产周期、生计需求的限制。而现行的草畜平衡制度在这两个基本环节的处理上采取了简单化、标准化的思路,导致该制度不能有效执行。文章认为,在资源时空异质性异常显著的干旱半干旱草场,目前将＂草畜平衡＂作为落实到每一微观牧户的实施手段,其可行性值得商榷,草场管理中更应该侧重生态系统的弹性管理,而不仅仅是关注作为阈值的承载力本身。

摘　要： 通过对现行草地适宜载畜量推算方法的实例分析，对以此为基础的草地载畜量计算方法进行了评述，对现行方法中所设置的一些参数的合理性和必要性进行了剖析。本研究认为，随时间推移，草地畜牧业的生产方式有很大改变，现行载畜量计算方法在理念上比较落伍，在参数选择上存在缺陷，已经不能适应现阶段的草畜平衡管理需求。

对现行的草畜平衡监测和管理方法进行了剖析,指出了其机制上存在的缺陷和管理中存在的问题;根据北方草原地区草地生产力和家畜需求间存在着明显季节性差异的特点,提出了按"草地资源限量,时间机制调节,经济杠杆制约"思路对草畜平衡制度进行改革的设想。

草原承包责任制的落实改变了草原上几千年的生产经营格局，牧户成为草原利用的基本单元。在气候变化与气象灾害的适应性成为当前全球性的热点与前沿科学领域的背景下，对牧户经营的气候响应过程进行研究，具有重要的科学与现实意义。在草地农业系统理论体系下，基于“感知-适应”分析框架，采用参与式农户法，辅以气象数据，以北方草原7个生态区域1475个牧户为对象，研究了“草畜-经营”界面的气候响应行为，探讨了牧民感知的信息传导途径，分析了牧户经营关键节点的气候适应策略，研究表明： （1）1980-2009年，北方草原气候变化显著。对温度而言，内蒙古草原区以0.63℃/10a的速率上升（R~2=0.58，P0.01），新疆天山北坡山地草原区以0.51℃/10a的速率上升（R~2=0.31，P0.01），各地温度趋于同步升高；内蒙古地区（-8.48mm/10a）与新疆天山北坡地区（+5.02mm/10a）降水变化不显著（P0.05）。 （2）与气候变化事实相比，不同地区牧民一致感知降水显著减少（χ~2=13.33，P=0.21），而对温度变化的判断却具有区域分异性（χ~2=27.19，P=0.02），表现出对气候变化感知的偏差；牧民对极端干旱年份感知以夏旱敏感型为主，不同时间尺度以季尺度解释力最强。基于气候变化趋势感知偏差、干旱年份感知的季节敏感性及时间尺度依赖性3个现象，提出传导感知假设，进一步研究实证，降水感知受草场变化等环境信息的传导，导致牧民对降水变化的“过度应激”，而温度感知则不具有传导性，表现为“亏缺应激”。同时发现，降水日数等节律指标比降水量变化更为敏感（P雨日P雨量），是引发牧民对降水感知偏差的重要因素。 （3）气候变化及气象灾害对牧户的影响主要表现于气象灾害，其中干旱（84.30%）是影响牧户经营的关键因子，牲畜（92.55%）、草场（88.74%）其主要作用介质，购草、卖畜是牧户对气象灾害短期响应的主导策略，分别为保畜与减畜策略，比较而言，保畜策略（88.27%）更为常见。可见，牧户经营对气象灾害的短期响应过程发生于“草畜-经营”界面，草、畜2因子是反馈的关键节点。 （4）与对北方草原退化成因的科学研究结论相反，93.38%的牧民认为降水减少是主要（43.05%）或唯一（50.33%）原因。尽管存在感知的偏差，牧户经营对气候变化等具有长期响应行为，接羔与出栏时间、畜种结构、饲草供给模式仍发生了变化，更适应于气候与草场资源的变化。其中，接羔时间提前约25d，接羔集中期-4℃线前移约10d，气候变暖起到了重要作用；小畜比例增加，更适于1a为周期的生产节律（R~2=0.43，P0.01）。 （5）研究认为，牧户生产系统是草地农业系统的最小完整单元，由气候、草场、牲畜、经营等要素构成，其主要过程是，在经济、生态等原则下，经营者根据气候波动对草地农业生产的干扰，通过功能响应，适应性地调节草畜间的物能平衡关系，使得农业产出最大化，风险最小化，在此过程中，经营者是关键调节因子，环境感知是响应策略产生的重要信息途径。

内蒙古草原面积约8.67x107hm2,在确保区域乃至今全国的生态、经济建设及社会稳定等方面都发挥着重要作用,但受到超载过牧、气候变化等因素综合影响,草原退化严重,草畜矛盾突出。草原退化问题已引起社会各界的普遍关注。其中,草畜平衡被列为草原保护的三大措施之一,其目的是建立合理的载畜量标准,合理利用草原资源,实现草原畜牧业的可持续发展。但越来越多研究发现,草畜平衡政策

Soil water storage (SWS) is the critical factor influencing wheat yield in dryland area. A field experiment was carried out in Wenxi County , Shanxi Province from July 2009 to June 2012 (three cropping seasons) to study the effect of tillage during fallow period on annual SWS and wheat yield. Compared to no tillage (NT), deep plowing (DP), subsoiling (SS) increased SWS in 0–300 cm soil layer at sowing stage by 63–91 mm in dry year, 41–70 mm in normal rainfall year and 54–74 mm in humid year. The annual SWS efficiency was much improved by tillage during fallow period, especially the late growth stage of wheat in dry and humid years, resulting in increases of grain yield and yield components. In dry year, wheat yield was enhanced as high as 34% (SS) and 45% (DP). In normal rainfall year, spike number, grain number per spike, and grain yield significantly increased in DP and SS compared to NT. In yield components, spike number received the largest effect of tillage, either DP or SS, under normal and rich rainfall conditions. In DP and SS treatments, spike number had close correlation with 120–180 cm soil water reduction from sowing to jointing and 60–120 cm soil water reduction from jointing to anthesis, grain number per spike was correlated with 60–120 cm soil water reduction from sowing to jointing, and grain yield was correlated with 60–120 cm soil water reduction from jointing to anthesis and 120–180 cm soil water reduction from anthesis to maturity. Clear, tillage during fallow period could significantly increase rainfall productive efficiency and water use efficiency in rainfed field. DP and SS have positive effects on SWS during fallow period and utilization of water in deep soil layers. The improved water utilization is the basis for improved yield components and high yield ultimately. Tillage during fallow period is recommended with DP practice in dry and normal rainfall years and SS practice in humid year.

为明确旱地小麦通过休闲期耕作实现蓄水增产的技术途径, 2009—2012年连续3个小麦生长季, 在山西闻喜县进行了休闲期深翻、深松或无耕作的田间试验, 以明确不同耕作措施对土壤水分变化、小麦产量形成的影响。结果表明 , 深翻和深松处理播种期0~300 cm土壤蓄水量增加, 枯水年增加63~91 mm, 平水年增加41~70 mm, 丰水年增加54~74 mm, 尤其在枯水年和丰水年生育后期蓄水效果仍显著, 休闲期土壤蓄水效率显著提高, 枯水年提高147%~205%。深翻和深松处理在枯水年和丰水年可促进小麦生育后期吸收300 cm土层土壤水分, 使产量和产量构成因素显著提高, 尤其在枯水年产量提高34%~45%。在平水年, 穗数、穗粒数和产量显著提高, 且在平水年和丰水年深翻和深松处理对产量构成因素中的穗数影响最大。深翻和深松处理后降水生产效率和水分利用效率显著提高。不同降水年型休闲期耕作条件下, 穗数与播种至拔节期120~180 cm、拔节至开花期60~120 cm土层土壤贮水减少量关系密切, 穗粒数与播种至拔节期60~120 cm土层关系密切, 产量与拔节至开花期60~120 cm、开花至成熟期 120~180 cm土层关系密切。 总之, 在本研究条件下, 旱地小麦休闲期深翻或深松耕作有利于蓄积休闲期降水, 改善底墒, 尤其枯水年的效果更为明显; 有利于增加土壤水分, 促进小麦向深层吸收土壤水分, 优化产量构成, 实现增产。在枯水年和平水年, 以休闲期深翻效果较好, 在丰水年以休闲期深松效果较好。

采用定位监测法,对黄土丘陵沟壑区不同降水年型下旱农坡地、刺槐林、沙棘灌丛和白羊草地土壤水分的时空变化规律进行了分析.结果表明,降水年型对研究区不同植被类型土壤水分的季节变化和剖面垂直变化均有一定影响.旱农坡地平水年土壤水分的季节变化平缓;枯水年雨季前土壤水分缓慢减小,雨季后显著增加;丰水年则整体增加,且雨季后增加明显.刺槐林、沙棘灌丛和白羊草地平水年土壤水分的季节变化表现为整体降低;枯水年沙棘灌丛土壤水分先减后增,刺槐林与白羊草地呈"W"型曲线变化,两个最低值均出现在6月和8月;丰水年沙棘灌丛和刺槐林土壤水分的季节变化呈"V"型,白羊草地的波动较大,最低值出现在8月.旱农坡地枯水年的土壤水分活跃层和次活跃层深度较平水年下移,丰水年次活跃层消失;丰水年和枯水年,刺槐林和白羊草地土壤水分活跃层深度均较平水年下移,沙棘灌丛则上移.

Alpine grassland ecosystems on Tibetan Plateau are highly sensitive to climate change. How these ecosystems response to climate change is a great concern. Based on the past five years researches, this paper briefly reviewed the responses of these ecosystems to climate change from the aspects of phenology, plant productivity, and carbon cycle, and the adaptive management to climate change. There are inconsistent conclusions so far. Most of the researches indicated that warming advanced the plant phenology and increased the primary productivity of alpine meadow, while opposite trends were observed for alpine steppe, suggesting that different plant communities in different regions could have different modes in response to the temperature change in different seasons. Similarly, there are controversial conclusions about the responses of plant species diversity and carbon sink/source to climate change because of the differences in spatial and temporal scales and research methods. Therefore, further researches are needed to integrate the spatial and temporal researches and to strengthen the studies of ecological processes and mechanisms.

青藏高原高寒草地生态系统对气候变化高度敏感，其如何响应和反馈气候变化一直以来受到极大关注。本文系统综述了近5年来有关青藏高原草地生态系统在物候、生产力、碳循环等方面对气候变化的响应过程以及应对气候变化的适应性管理的最新研究成果，发现气候变化对高寒草地生态系统的诸多影响还存在很大的不确定性。多数研究结果表明，增温使高寒草甸的植被物候提前和初级生产力水平提高，而高寒草原有相反的影响趋势，说明不同地域、不同群落类型对不同季节温度变化的响应模式不同。而气候变化对物种多样性和碳循环有关过程的影响结果尚没有一致的结论，时空尺度和方法上的差异可能是导致不同结果的主要原因。因此，建议在增强时空异质性的响应与反馈研究的同时，更需要加强生态过程和机理的研究。

As the most serious challenge that the humankind is facing, climate change has been strengthened vulnerability in many countries and regions, and how to scientifically adapt to climate change has become the global issue of common concern to the international community today. The impact of climate change on farming people depending on the nature resource is especially remarkable, and understanding farmers’ adaptation mechanism and process is very important to effectively make the adaptation policy. As the basis of understanding the human response action, public perception has provided a new perspective to verify the farmers’ adaptation mechanism and process about climate change. Based on the recent theoretical and empirical developments of farmers’ perception and adaptation, the impact of climate change on the farmers’ livelihood was analyzed, and the main adaptation obstacles which the farmers faced in response to climate change were summarized systematically. Then, we analyzed the relationship between the farmers’ climate change perception and adaptation, illuminated the key cognitive elements in the process of the farmers’ climate change adaptation and introduced the framework to analyze the relationship between the farmers’ climate change perception and adaptation. At last, this review put forward the key questions which should be considered in study on the relationship between the farmers’ climate change perception and adaptation.

气候变化是21世纪人类面临的最严峻挑战之一,加剧了许多国家和地区的脆弱性,人类如何适应气候变化已成为当前全社会普遍关注的话题.气候变化对以自然资源为生计基础的农业人口的影响尤为显著,更好地理解农户对气候变化的适应机制和适应过程对于制定有效的适应政策非常重要.公众感知作为理解人文响应行动的基础,已为探明农户对气候变化的适应机制和适应过程提供了一个新视角.本文基于国内外农户对气候变化的感知和适应的理论研究和实践进展,在分析气候变化对农户生计的影响、系统总结农户面临的主要适应障碍的基础上,梳理了农户的气候变化感知与适应的关系,阐释了农户适应气候变化过程中的关键认知要素,介绍了农户对气候变化的感知与适应关系分析框架,提出了农户对气候变化的感知与适应关系研究中应关注的关键问题.

甘南藏族自治州是甘肃省的主要畜牧业基地，也是黄河重要水源补给区之一，草地畜牧业对于当地的草地生态平衡、牧民生产生活、区域经济发展都有重大意义。上世纪80年代以来，甘南牧区人口剧增、过牧超载问题日益严重，直接威胁当地草地生态稳定和草地畜牧业的可持续发展。　　 国家“863”计划数字农业专题课题“甘南牧区草畜数字化管理系统”(2007AA10Z232)，以卫星遥感、牧业调查和统计年鉴资料为数据来源，结合3S技术，建设用于草地监测评价、草畜平衡诊断、辅助决策和数据共享的在线数字化系统。　　 在该课题支持下，本研究对甘南州的草畜平衡现状进行了...

In this paper, the distribution of NPP of natural vegetation in China was given according to a new NPP model. This NPP model was based on ecophysiological feature and regional evaportranspiration model relating the two well known balance equations on the earth’s surface, water balance equation and heat balance equation. The changing pattern of NPP in China was also given under doubled CO2 concentration. This study would help to make good use of natural resources and to make scientific count-measures under global climate change.

本文根据已建立的植物生理生态学特点与水热平衡关系的植物净第一性生产力模型对中国自然植被的净第一性生产力现状及全球变化后的自然植被的净第一性生产力进行了分析，给出了中国陆地生态系统自然植被的净第一性生产力在全球气候变化条件下的变化图景，为合理开发、利用自然资源，以及监测和预测中国陆地生态系统自然植被净第一性生产力的变化及应采取的策略提供了科学依据。

In this paper,the effect of absorption and yield in grain,straw,root of spring wheat under different fertilization were studied by field plot experiment.The results showed that,Scientific and rational use of fertilization not only increased spring wheat yield,but also increased N,P and K content in spring wheat to some extent,Which compared with control.The treatment of NPKis most significant,the to tal up take of nitro gen,phosphorus and potassium increased respectively by 156.9%,94.4%and 112.8%,The maximum of nutrient index of nitrogen,phosphorus and potassium is respectively 0.730,0.778,0.130.Applying organic manure and chemical fertilizer could increase spring wheat yield,The output increased by 32.8%-214.2%,the effect of Nitrogen fertilizer increasing production is obvious.Combined application of nitrogen,phosphorus and potassium has best effect,has significantly effect on increasing crop N,P and K content and yield.

通过田间小区试验,研究了不同施肥对春小麦籽粒、秸杆和根系养分的吸收状况及产量的影响.结果表明,与对照(CK)相比,科学合理施肥不但在一定程度上增加了春小麦N、P、K养分含量,而且大幅度的增加了春小麦的产量,以化肥氮磷钾(NPK)处理的效果最为显著,其氮、磷、钾素的总吸收量分别增加了156.9%、94.4%和112.8%,氮、磷、钾的养分收获指数最大分别是0.730、0.778和0.130.增施化肥及有机肥均能促进春小麦产量的增加,增产幅度为32.8%~214.2%,其中氮肥的增产效果最为明显,以化肥氮磷钾(NPK)配施处理最优,在促进作物氮、磷、钾养分浓度的提高及产量的增加效果上最为明显.

Dry-Weight-Rank Method (DWR) is a method of estimating the substance and biomass of grassland through the corrected quadrat and establishing the calculation models. The method was originally widely used in pasture, rarely for grassland. However, in recent years, it had been gradually extending to grassland in Australia and Europe. To prove that if this method could apply to the investigation of grassland, we chose the alpine meadows of Luqu in the south of Gansu Province and the typical steppe of Siziwangqi in Inner Mongolia as the study area, which used to compare the dominant species and aboveground biomass using DWR and conventional method (CM). The results showed that the dominant species are Kobresia pygmaea, Carex atrofusca, Potentilla anserine by CM and Kobresia pygmaea, Poa pratensis, Potentilla anserine by DWR in alpine meadow, and Stipa krylovii. Agropyron cristatum, Cleistogenes squarrosa by CM and DWR in typical steppe. There were no significant difference in the total aboveground biomass in alpine meadow (73.18 g·m-2, DWR；82.84 g·m-2，CM)（P>0.05）and the same applies totypical steppe (89.67 g·m-2, DWR；88.10 g·m-2，CM)（P>0.05) between two methods. In a conclusion, DWR is suitable to a certain extent for evaluation of natural grassland in China.

系列干重法（Dry-Weight-Rank Method，DWR）是一种通过矫正样方建立反演模型，大范围估测草地植物组成及生物量的方法。该技术最初普遍应用于栽培草地，极少用于天然草地。近年来，澳洲和欧洲逐渐将此项技术扩展。为证明该方法能否适用于我国天然草地的调查，本研究以甘南碌曲高寒草甸和内蒙古四子王旗典型草原为试验区，将DWR与样方技术（Conventional Method，CM）做比较。结果表明，高寒草甸中，以常规方法测定的优势种为高山嵩草（Kobresia pygmaea）、黑褐苔草（Carex atrofusca）、鹅绒委陵菜（Potentilla anserine），以DWR方法测定的优势种为高山嵩草、草地早熟禾（Poa pratensis）、鹅绒委陵菜；典型草原以常规方法和DWR方法测定的优势种均为克氏针茅（Stipa krylovii）、冰草（Agropyron cristatum）和糙隐子草（Cleistogenes squarrosa）；且两种技术测得的高寒草甸地上总生物量(73.18 g·m-2，DWR；82.84 g·m-2，CM)差异不显著（P>0.05），典型草原植被地上总生物量（89.67 g·m-2，DWR；88.10 g·m-2，CM)亦不显著（P>0.05）。DWR方法在我国天然草地植被评估中具有一定可行性。

According to the Comprehensive and Sequential Classification System(CSCS), the grazing system is classified into eight categories as alpine steppe, desert, semi-desert, subtropical forest shrub, typical steppe, meadow steppe, temperate forest shrub and tropical forest shrub. The succession stages of grazing systems are original nomadism, extensive nomadism, overgrazing and modern grazing. According to long-term productivity dynamic of three grazing systems, China is still in the overgrazing stage, and converting to modern farming system. Average production capacity of grazing system in China is 18.04 APU·ha -1 , and the total production capacity is 6.35 billion APU. The national meat production is 2.959 million t·a -1 . The grazing system was structurally overloaded in China, namely the overall overload. Meanwhile, there are still potential increase in seasonal utilization in some region. At present, the potential to increase grassland productivity potential is about 0.5 to 2 times in China, the key measure is the transform into the modern grazing systems in China.

根据草原综合顺序分类法(Comprehensive and Sequential Classification System,CSCS)划分了高寒,荒漠,半荒漠,亚热带森林灌丛,典型草原,草甸草原,温带森林灌丛,热带森林灌丛8个类型的放牧系统.放牧系统经历了原始游牧,粗放游牧,过度放牧和现代化放牧4个演替阶段,根据3个类型放牧系统生产力长期动态,我国主体仍为过度放牧系统,但开始向现代化放牧系统转变.我国放牧系统生产力平均18.04 APU·hm -2 ,总计63.50亿APU,每年可产肉295.9万t.我国放牧系统存在结构性超载,即整体超载,但是部分区域,部分季节存在放牧利用不足.目前,我国草原增产潜力为0.5~2倍,关键途径是实现草原放牧系统的现代化转型.

Based on equilibrium theoretical models, the response of vegetation to grazing pressure is linear and reversible, and can be manipulated predictably with stocking rates. This equilibrium-based theoretical model advocates a conservative stocking strategy to maintain internal ecosystem regulation and stability. The management goal is to maintain a balance between stocking numbers and feeding resources. In contrast, 'new rangeland science' based on non-equilibrium ecological dynamics placed greater emphasis on external disturbances as drivers of ecosystem behavior. The ‘new science’, proposes that plant composition and biomass in semi-arid rangelands are primarily driven by rainfall and not by grazing pressure. Management of such systems should be opportunistic and take advantage of, or create, conditions which allow switches to a more desirable state. There are two major approaches: plant- or animal-oriented, to determine rangeland carrying capacity (CC). The traditional technique for determining CC is to calculate the total amount of forage at the end of the growing season, multiply this by a correction factor, and then divide by the average yearly feeding requirements of a livestock unit. Using total herbaceous forage productivity as the single criterion to predict the livestock support capacity has been criticized because biomass quality and feeding value for livestock and livestock nutritional needs are largely ignored. Based on research progress, the development and evolution, controversy in the application of the CC concept are summarized. The plant-, animal- (including standard hay-, total digestible nutrients- digestible crude protein- and energy-oriented) oriented CC was also compared. It is evident that in view of the seasonal variation in nutrient content of natural herbage, animal-oriented permissible stocking rates on the whole tend to be lower than those predicted by the plant-oriented approach. The most complete approach to evaluate primary and secondary productivity of rangelands should combine plant- and animal-based methods, rather than just plant oriented. In the case of a conservative grazing strategy, stocking rate was stable and grazing pressure fluctuated while for an opportunistic grazing strategy, stocking rate was unstable and grazing pressure was stable. Both equilibrium and non-equilibrium dynamics are found in rangelands, often at different times or governing different parts of the resource. Either conservative or opportunistic strategies could be correct, depending on the circumstances, including environmental variability and predictability, degradation and thresholds, property right regimes, discount rates, and market stability and prices. Finally, rangeland science and management are ultimately based on ecological models. In making management decisions, the specific model used is important because it determines both the expected ecosystem response to particular actions, as well as the strategies to attain desired conditions. The ecological model and grazing lands applications are summed up to provide reference for grazing management decision.

平衡理论强调家畜和草地资源之间的生物反馈,主张采取保守放牧策略保证草地生态系统的稳定性,草地管理的目标是调节草地牧草供给量和家畜饲草需求量平衡。基于非平衡理论的“新草地科学”,则强调气候因素尤其是降水,决定着干旱、半干旱区草地承载力,主张采取机会主义策略,充分利用草地并维持草地基况。传统上,草地载畜量的确定是先计算生长季末的草地产量,利用草地利用率等校正系数校正,再除以家畜的年平均需求量;但由于其没有考虑牧草质量、饲喂价值和家畜营养需求,载畜量估计存在误差,从而导致争议。本文依据国内外研究进展,回顾了草地载畜量概念的发展和演变,比较了草地产量载畜量、营养载畜量(包括标准干草载畜量、总可消化养分及可消化粗蛋白载畜量、能量载畜量)差异,归纳了草地载畜量在应用上的争议。本文指出,由于牧草养分的季节变化动态,采用家畜营养需求法估测的载畜量值通常较草地产量法为低,放牧实践上应采用2种方法相结合估算草地载畜量,根据估算数较低者确定草地载畜量有利于草地可持续利用和保护。草地通常既存在平衡态,也存在非平衡态;而基于平衡理论的保守放牧策略在放牧率和放牧压力上,与基于非平衡理论的机会放牧策略存在差异;放牧管理应结合气候条件、草地基况、草地产权制度、政府贴现与否及市场价格等因素,选择保守放牧策略或机会放牧策略,实现草地畜牧业生产的生态和经济效益。由于生态模型通过模拟草地对放牧的响应及放牧对草地的影响,是草地管理的基础,本文归纳了草地放牧管理相关的生态模型和放牧管理应用程序,以期为草地放牧管理决策提供参考。

The traditional technique for determining grassland carrying capacity (CC) is to calculate the total amount of forage at the end of the growing season,multiply this by a correction factor,and then divide by the average yearly feed requirements of a livestock unit. But there has been no consensus on the correction factors and time span. For convenience of management,ananimal unit (AU) is defined,based on the grazing pressure on grassland or grass consumption of certain specific animals,as the standard so other animals can be converted into animal units by comparing the same items. Currently,the most widely used animal units are animal unit (cow unit) and sheep unit (SU). But the AU is often defined on a live body weight (LBW) basis,which does not distinguish between physiological stages that may affect forage intake. What’s more,some forage species are not preferred by some kinds of livestock,and some ranges are better suited to one kind of livestock than to another; Animal units for different animal species should be adjusted based on the average dietary overlaps of these animal species on a specific type of range for calculating pasture-specific substitution ratios. It is important for pastoralist to be aware of use levels,residual vegetation and other grazing impacts during the period of use as well as utilization at the end of the growing season. Various methods were developed to estimate proper utilization rates,which can fall into two categories:estimation and measurement. The rule-of-thumb takes half-leave,half-use has been a standard in the range management profession for years. But forage output fluctuates considerably between years in response to changing climatic conditions and the concept of utilization rates means how it should be used in pasture management and has led to some confusion because a variety of ways in calculating pasture utilization rates are often not clearly defined. Furthermore,the choice of a proper use value has a profound effect on the estimate of CC. Based on research progress,the concept,measurement method and application dispute of parameters such as grassland output,proper utilization rate,livestock substitute rate et al . for CC calculation are summarized. The calculation method and adjustment factors for CC are also summarized to provide reference for grazing management decisions.

根据生长季末草地产量,利用草地利用率等校正系数校正,除以家畜牧草需求量,是草地载畜量最基本的计算方法。但在草地产量及其测定时间跨度、草地利用率和家畜折算系数等参数的确定上存在争议。基于放牧压力或家畜采食量需求的家畜单位用于不同畜种的折算,牛单位和羊单位是常采用的家畜单位,但家畜单位主要依据家畜活体重量确定,对家畜代谢体重,以及混群放牧中因家畜食性差异造成的采食重叠考虑不足;草地利用率是放牧管理的重要参数,主要根据放牧经验和试验方法确定,实际应用中通常遵循“采食一半、保留一半”的经验法则,但在不同草地类型、地形差异、水源距离等因素影响下,草地利用率并不确定,其估计和测定方法也存在争议。此外,不同草地利用率下的草地载畜量差异很大。本文结合国内外研究进展,综述了草地载畜量估算中草地产量、草地利用率、家畜单位等参数的概念、确定方法和应用上的争议,总结草地载畜量的计算方法及校正因子,以期为草地放牧管理决策提供参考。

利用遥感数据、实际牲畜量等资料和已有的研究结果,计算了2000~2012年呼伦贝尔草原区各植被亚区产草量、载畜量及超欠载率,并结合降水数据分析影响各植被亚区草畜平衡的主要驱动因素,结果表明:2000~2012年呼伦贝尔草原各植被亚区草畜平衡状况差异较大,产草量的差异是驱动各植被亚区草畜平衡呈现不同状况的主要原因;在典型草原地区,降水量是草地草畜平衡的主要驱动因素,单纯以控制牲畜数量的方式很难实现长期的草地草畜平衡。基于时空异质性综合考虑不同驱动因素影响下的草原区域的特点,并采取相应调控方式,更有利于保证不同草原区的草畜平衡。

Estimating carbon storage in terrestrial ecosystems has been a central focus of research over the past two decades because of its importance to terrestrial carbon cycles and ecosystem processes. As one of the most widespread ecosystem types, China’s grasslands play an important role in global change research. The grasslands in China, which are distributed primarily throughout the temperate regions and on the Tibetan Plateau, were classified into 17 community types. In the present study, a statistical model was established to estimate grassland biomass and its geographical distribution in China based on a grassland inventory data set and remote sensing data (Normalized Difference Vegetation Index) using GIS and RS techniques. We found that there was a significant correlation between aboveground biomass density and the maximum annual NDVI when expressed as a power function (R2=0.71, p<0.001). The aboveground biomass was estimated to be 146.16 TgC (1Tg=1012 g) and belowground biomass was estimated as 898.60 TgC (6.15 times of the above biomass) for a total biomass of 1 044.76 TgC. This value accounts for about 2.1%-3.7% of the world’s grassland biomass. The grassland biomass is distributed primarily in the arid and semiarid regions of Northern China and the Qinghai-Xizang Plateau. The average biomass density of China’s grasslands was 315.24 gC·m-2, smaller than the world average. The aboveground biomass density decreases from southeastern China toward the northwest corresponding with changes in precipitation and temperature. Furthermore, aboveground biomass density reached the lowest levels at 1 350 m elevation and peak levels at 3 750 m above sea level which most likely is related to China’s three-step topographical background. The ratio of total biomass of grassland to forest biomass in China is 1/4, much higher than that of the world, suggesting a greater contribution of grasslands to China’s carbon pool.

草地生态系统是陆地生态系统分布最广的生态系统类型之一，它在全球变化中的作用越来越受到重视。利用中国草地资源清查资料，并结合同期的遥感影像，建立了基于最新修正的归一化植被指数(NDVI)的我国草地植被生物量估测模型，并利用该模型研究了我国草地植被生物量及其空间分布特征。结果表明：草地植被地上生物量与当年最大NDVI值具有很好的相关关系，两者可以用幂函数很好地拟合(R2=0.71, p<0.001)。我国草地植被总地上生物量为146.16 TgC(1 Tg=1012 g)，主要集中在北方干旱、半干旱地区和青藏高原；总地下生物量为898.60 TgC，是地上生物量的6.15倍；而总生物量是1 044.76 TgC，占世界草地植被的2.1%～3.7%，其平均密度约等于315.24 gC·m-2，低于世界平均水平。我国草地植被单位面积地上生物量水平分布趋势为：东南地区高，西北地区低，与水热条件的分布趋势一致；从垂直分布看，在海拔1 350 m和3 750 m处分别出现了波谷和波峰，与我国特有的三级阶梯地势有着密切的关系。此外，我国草地植被生物量为森林的1/4左右，显著大于世界平均水平，说明我国草地在碳平衡中的贡献相对较大。

近年来,青藏高原东部高寒草地出现了明显的草地退化情况,这不仅严重限制了该地区牧民生活和收入水平的进一步提高,阻碍了该地区牧业经济的可持续发展,还会对黄河中下游地区的生态安全造成极大的威胁。牧民作为利用草地资源的微观主体,其决策行为对草地资源的可持续利用具有决定性的作用,直接影响草地质量的好坏。如果想真正了解和解决草地退化问题,必须从牧民这一微观主体的决策行为过程入手。本文以地处青藏高原东部的玛曲牧区为例研究牧民决策行为及其对高寒草地的影响。 本文前两章主要介绍研究背景、研究目的并梳理了国内外相关文献,对以往的文献进行了综述、介绍了决策行为研究的相关理论；第三章介绍了草地退化问题的原因及牧民决策行为对草地质量的影响；第四章从牧民决策偏好入手,选取配对比较法对牧民的决策目标集进行比较,分析了牧民决策行为的目标偏好情况。第五章、六章在第四章的基础上分析了牧民决策行为的影响因素,提出了相关对策,最后对得出的结论进行了总结,提出了本文尚且存在的问题和需要进一步改进之处。

本文结合行为经济学理论及实证分析,探讨了三江源草地生态退化中牧户运用生计策略进行保护行为决策的框架,通过多分类Logistic模型分析了影响牧户选择限制放牧、生态移民和产业移民等不同保护模式行为的影响因素.结果表明:①年龄较大的、生计水平较低、较偏远的牧户被动地选择了机会损失和风险较小的限制放牧或生态移民方式,而年轻的、生计水平较高、离城市距离较近的牧户更愿意选择产业移民的生态保护方式;②三江源牧户是基于有限理性,而选择了福利损失相对较小的生态保护行为,这是牧户生计策略选择的结果;③着眼于增加牧户选择的机会和促进牧户可替代生计的多样化,以期降低牧户选择生态保护行为响应后的各种风险,以及提高牧户面对风险的能力,并有效地补偿牧户选择生态保护后所遭受的福利损失,是促进牧户积极主动地参与生态保护行为及区域实现生态经济可持续的关键.

草地资源是我国干旱半干旱地区生态安全的重要屏障,也是草地畜牧业发展的重要物质基础。大面积的草地退化不仅直接影响牧民的生产活动与牧区的经济发展,也是许多区域性生态灾难的主要诱因。草地退化问题已经引起党和国家的关注、成为学术界研究的一个热点问题。大多相关研究集中在区域内草地退化的表现和原因,而将牧民作为研究对象,从牧民的生产生活出发探究草地退化之间成因、寻求抑制草地退化措施的研究尚不多见。本文认为:农民问题是我国“三农”问题的核心,不从农民的权益出发,就不可能从根本上解决“三农”问题。近年来,行为经济学、实验经济学的发展使经济学家们逐步把目光转向经济发展的微观层面去探索经济主体的行为对经济发展的影响。对农户经济行为的研究已经成为发展经济学一个理论前沿问题就是对这一转变的很好映证。基于以上认识,本研究以新疆阿勒泰传统牧区青河县和富蕴县牧民为研究对象,通过探索牧民生产决策行为与草地退化之间的内在关联性,综合分析影响牧民生产决策的主要因素以及各因素与牧民生产决策之间的互动关系,旨在从中发现抑制草地退化的路径与措施。 本研究通过文献分析、专家讨论和实地调研确定了研究区域牧民生产决策的目标集,该目标集包含:过轻松自由的放牧生活;将牲畜、草场作为财产留给自己的下一代;做一个受人尊重的牧民;通过饲养牲畜并在将来价格较高时销售、以获得更多的收入;提高目前家庭的生活水平五个目标。利用配对比较法确定各种目标重要性,其中将牲畜、草场作为财产留给自己的下一代是最为重要的生产目标,而通过饲养牲畜并在将来价格较高时销售以获得更多的收入次之。然后,分别以这两个目标最大化为生产决策的目标函数,构建新疆牧民生产决策的线型规划模型。利用该模型,采用情境分析法模拟分析了牧民对草地退化影响的认知、草地资源利用的外在约束、畜产品市场变化和生产技术等因素变化状况对牧民生产决策的影响。对模拟结果的分析表明:(1)以收入最大化为目标的生产决策比以规模最大化为目标的生产决策更有利于缓解草场压力;(2)牧民的自我约束对抑制草地退化的效果不小于来自政府强制性约束的效果;(3)在目前超载过牧的情况下,价格上涨有助于降低饲养规模;(4)降低生产风险的生产技术进步有助于减少饲养规模。基于以上分析,本研究进一步考察了草地产权制度、草畜平衡管理、有机畜牧业发展等政策或政策倾向在研究区域实施的前景,阐述了本研究对这些政策及政策倾向的基本观点:以草地资源私有化为指向的产权改革难以内化草地资源利用的“外部性”;草畜平衡管理需要牧民内在变化相配合;有机畜牧业是新疆草地畜牧业可持续发展的方向。 以这些分析结果与观点为基础,本研究提出一些有助于保护牧民利益、抑制草地退化的政策与建议:(1)建立草地资源动态监测体系;(2)促进两个转变:牧民对草地退化影响的认知向行为转化、牧户作为单纯的生产单位向生产与生态保护单位相统一转变;(3)在稳定、完善草场承包制度的基础上,以草地使用权流转为切入点,探索草地资源利用新机制;(4)政策与措施的指导思想要由单纯追求畜产品的供给向发挥草地生态系统多功能性转变;(5)将有机畜牧业可以作为转变生产方式的一个选择进行试点与发展

呼伦贝尔草原属中温带大陆季风气候。近年来,在全球性的气候异常、牧区人口过快增加的背景下,90%的天然牧草出现不同程度的退化现象。气侯变化是诱发草原退化最重要的因素之一,分析气象要素的分布特征、时空变化规律对牧草生长发育的影响具有重大意义。 本文从呼伦贝尔草原的气象要素(气温、降水等)变化特征出发,利用50多年(1951—2004年)的气象资料和牧草监测数据,分析了该区域的气温、降水构成特征及变化规律,利用相关系统和积分回归的分析方法,定量寻找气象因子对牧草生长发育的关系。结果表明: 在气候变暖的前提下,气温升高,牧草返青期提前。资料表明,近10年牧草返青期平均提前7—12天,尤其是在牧草生长期,温度升高,牧草生长加快,牧草生长高度增加,牧草的生长期在缩短,再生草生长时间延长。 通过对降水变率的统计表明:一年中春季降水变率最大,夏季最小,说明了春季干旱较频繁,对牧草返青生长十分不利。由于受季风气候影响,降水多集中在温暖季节,具有雨热同季的特点,有利于农作物生长发育。但降水季节分配不均匀,农作物生长发育缓慢,往往导致牧草在秋季霜冻前不能成熟。 天然草地牧草生长发育受环境条件影响很大,牧草的发育期和干物质累计年际间和年内有明显的变化。利用多年牧草观测资料,分析了影响草地牧草的主要气象要素并建立了呼伦贝尔草原主要牧草物候发育和干物质累积模型。

我国是草原资源大国。草原畜牧业是我国畜牧业不可或缺的组成部分。加强草原保护建设是增加农牧民收入、促进牧区繁荣和边疆稳定的需要;是建设现代农业和维护国家生态安全的需要。目前草原的突出问题是草原畜牧业发展与草原生产能力不协调,草原生态退化面积迅速扩大,严重影响草原畜牧业的可持续发展和牧区经济社会的稳定和发展。采取有效措施,促进草畜平衡,从根本上扭转草原生态退化的局面,促进草原牧区畜牧业的可持续发展,具有十分重要的意义。 本文运用定量定性相结合、实证研究与规范研究相结合等方法,在以下几方面进行了有益的探索:一是对目前我国主要牧区草原的草畜平衡状况进行了估算;二是对未来5年主要牧区省份草畜平衡情况进行了预测,提出了不同增长速度下草原载畜量的供需缺口;三是对草畜平衡的相关影响因素进行了定量分析。四是在已有分析的基础上,对实现草畜平衡可能的政策途径进行了分析评估,并提出了在牧区通过补贴限制牲畜头数、加快牧区劳动力转移等政策措施。 我国草原资源总量大而人均少,类型多而分布广;产量低,生态脆弱。近十几年来主要牧区草原退化严重。开垦、人为破坏和超载过牧是主要退化原因。草原建设速度赶不上退化速度。 草原畜牧业在我国畜牧业中占有重要的地位。近二十年来,牲畜头数增幅下降,畜产品产量却保持了较高的增幅;牲畜结构和产品结构都在顺应市场需求的方向变化;草原资源对牲畜增长速度已开始产生制约作用。 草畜平衡是保护草原资源和促进草原畜牧业发展的核心问题,未来几年草畜平衡任务十分艰巨。草畜平衡是一种理念,是发展战略和发展道路,也是一种制度。假定草原牧区理论载畜量不变,牲畜幅度与前几年大致相当,2010年天然草原理论载畜量只能满足约一半的需要量。 人口、牧户收入和生产规模以及市场和技术因素等是草畜平衡的重要影响因素。牧区人口的增加对草原理论载畜量的增量有明显的负影响,人口增量每增加一人,载畜量的增量减少接近8个羊单位。牧户收入对人工种草和草原围栏建设有显著影响。牧户生产规模对草场围栏、棚圈建设和人工草地等建设有较明显的影响。牧民的文化程度和市场价格影响牲畜存栏规模。 实现草畜平衡政策途径各有利弊,需统筹考虑,配套使用。对牧区来说,适度限制牲畜头数、加速牧民劳动力的转移应当作一项重要措施摆上议事日程。牧区还要结合禁牧休进行人工种草。舍饲半舍饲与三元种植结构调整相结合是半农半牧区实现草畜平衡的主要途径。草原承包制的完善、草原管理和牲畜饲养技术水平的提高也能促进草畜平衡。 本文的政策建议:一是完善草原承包制,从根本上调动牧民促进草畜平衡的积极性;二是启动限制饲养补助试点,直接降低草原负荷;三是加强牧民的培训,促进牧民向非牧产业的转移;四是扩大人工种草面积,提高牧草产量;五是在半农半牧区积极推进草田轮作和三元种植结构调整,增加专用饲料生产;六是大力促进生产方式转变提高舍饲半舍饲饲养比例;七是积极发展劳动密集型产业,为牧民就业创造条件;八是大力推广草原管理和畜牧业适应技术,提高草原利用效率。

本研究利用产量和利润最大化理论,基于随机抽样调查构建多元选择模型,探讨不同类型牧户放牧决策差异及导致牧户过度放牧的内在机制,分析牧民家庭收入、畜牧业科技推广、草地管理投入、牧户兼业行为和风险意识等变量对牧户放牧决策的影响,模拟不同政策组合下过度放牧牧户降低牲畜存栏量的意愿。研究表明,1)牧户生产决策受畜产品价格影响大,然而,不同质量畜产品价格差异小,导致牧民忽略畜产品品质而过度追求存栏量,引致草地禁牧政策失效;2)牦牛饲养比重对牧户减少牲畜存量的边际倾向值最大,比重每增加1单位,牧户意愿降低牲畜存栏量5.684单位,由于牦牛饲养草地需求较多,对是否降低存栏量敏感;3)大部分牧户倾向于选择经济效益,寻找兼顾生态与经济,能够有效提高牧户参与的区域生态经济发展战略是未来西藏牧区生态保护与经济发展策略的核心。